Useful reviews of the art of making satisfactory french fried potatoes that are suited to be cooked ultimately by the consumer by exposure to microwave energy are found in U.S. Pat. No. 4,590,080 of Pinegar, and U.S. Pat. No. 4,931,296 to Shanbhag. Such french fried potatoes will be referred to in this patent document as "microwavable french fries".
Desirable characteristics of microwavable french fries are light crisp outsides, tender mealy insides, a light brown color and a full potato flavour. It has been found difficult to produce satisfactory microwavable french fries, the result being too often too crisp, too soggy or lacking in flavour.
In the Pinegar patent, a method of preparing microwavable french fries is described which includes the step of parfrying potato strips under controlled time and temperature conditions, for example with two parfrying steps with an intermediate cooling step in which the potato strips are frozen to reduce the moisture content of the strips in accordance with a predetermined relationship of strip size, strip surface area and moisture loss during processing.
In the Shanbhag patent, believed to the most successful of the prior art methods, blanched potato strips are dust coated with starch granules derived from potatoes and then fried until the moisture content of the potato strips is from about 20 to 42 per cent by weight, with a final step of cooling of the potato strips.
Both patents teach reduction of water content. In the case of Shanbhag, water content is reduced to 20 to 42% and in the case of Pinegar typical initial water levels of 80% are reduced to about 50%.
While the Shanbhag process is believed to produce the more successful, that is, more palatable, french fry, it does not particularly address fat content. The Shanbhag product has a fat content in the order of 16% to 30% fat, while the Pinegar product has a fat content of between about 7% and 16%.
Boxes useful for cooking microwavable food products are known in the art. Such a box can be found in U.S. Pat. No. 4,590,349 issued May 20, 1986. This box contains a pair of microwave interactive layers one on each of a top panel and a bottom panel of the box. Each of the interactive layers assists in the cooking of foods placed on the layer. Using an interactive layer on each of the top panel and the bottom panel of the box allows the box to be place one way up for a first cooking period and then turned upside down for a second cooking period. The use of interactive layers on both the top and bottom of the box facilitates cooking of the food in the box in both cooking periods.
In one aspect of the invention there is provided a process for the manufacture of a relatively low fat microwavable french fried potato with desirable textural and taste characteristics. The present invention does not follow the prior art in which reduction of water content is taught but in one aspect teaches that water content should be reduced as little as possible and that water content should be greater than 60%, preferably between about 65 and 80%.
To obtain crispness of the finished product, the invention provides a process containing one step of treating the potato strips in a solution containing starch. It is believed that treating in a starch solution allows a thin concentrated layer of starch molecules to form within the top surface layer of the potato. On frying, the starch molecules become initially gelatinized and on subsequent reheating, as for example in a microwave oven, the starch molecules become dehydrated and form a crisp outer layer. Due to the effectiveness of the starch layer, moisture may be retained in the potato, and the resultant potato strip has high moisture content. Treating in a starch solution means that the starch enters the potato before a first frying step. This is believed to assist in preventing fat from being absorbed by the potato during subsequent frying steps, with the resulting product being relatively low in fat content, high in moisture content, while yielding a crisp final product on microwave heating.
There is also provided a method of cooking a relatively low fat microwavable french fried potato in which potato strips are contained within a box, the box is opened to lie flat and the potato strips are spread on the box and then exposed to microwave energy. The box has a consecutive top panel, side panel and bottom panel, with surrounding flaps. The potato strips are spread across the top panel, side panel and bottom panel for cooking. Preferably a susceptor board covers the top panel, side panel and the bottom panel.
A box for microwave cooking of potato strips includes a top panel, side panel and bottom panel, each of which has a susceptor board closely affixed to it. Thus the box, when opened to lie flat, forms a wide surface on which the potato strips may be placed for cooking.